Mold Removal Cost From Wood

Mold that has not penetrated past the wood's surface typically wipes away with a HEPA vacuum and an EPA-registered antimicrobial, a relatively inexpensive step. Mold that has been present long enough to stain into the wood grain requires actually removing a thin layer of the material to eliminate it, since the discoloration and spore structures have worked into the fiber, not just sat on top of it. A contractor should be able to point to specific joists or studs and explain which category each falls into rather than quoting the entire structure at the higher rate.

Hand or orbital sanding works on accessible flat surfaces like exposed joists but is slow and generates dust that needs full containment. Dry ice blasting (using pellets of frozen CO2) removes mold from irregular wood surfaces like beams and trusses without adding moisture back into the material, and it sublimates away instead of leaving residue, but the equipment rental and technician time make it pricier per square foot than sanding. Soda or media blasting sits between the two in both cost and abrasiveness, and is common on structural lumber that can tolerate a slightly more aggressive process than fine millwork or trim.

Wood that has softened, is structurally compromised, or shows mold that has fully penetrated through the cross-section (common in older sistered joists or sill plates near chronic moisture) should be replaced rather than treated. Paying to clean wood that a structural inspection would flag anyway is money that does not solve the underlying problem.